摘要
在搅拌头转速为1200 r/min、焊接速度分别为30,60,80 mm/min的工艺参数下,对AZ31镁合金进行搅拌摩擦焊试验。采用光学显微镜、万能试验机、扫描电镜和化学工作站分析不同焊接速度对试样的显微组织、力学性能和耐腐蚀性能的影响。结果表明,焊接接头由焊核区(SZ)、热力影响区(TMAZ)、热影响区(HAZ)和母材区(BM)4个区域组成。相比后退侧(RS),热力影响区(TMAZ)与焊核区(SZ)的分界线在前进侧(AS)更为明显。焊接速度从30 mm/min增加80 mm/min时,接头的抗拉强度和断后伸长率均先变大后减小,焊接速度为60 mm/min时抗拉强度达到最大,其值为190.3 MPa,此时可达母材(250.3 MPa)的76%。随着焊接速度的增加,耐腐蚀性能也呈现出先增强后下降的趋势,在转速1200 r/min、焊接速度60 mm/min的工艺参数条件下,耐腐蚀性能最佳,此时自腐蚀电位达到最大值−1.44 V,自腐蚀电流密度为最小值4.5×10^(−5)A/cm^(2)。
Friction stir welding(FSW)of AZ31 magnesium alloy was carried out under the conditions of rotating speed of 1200 r/min and welding speed of 30,60,80 mm/min respectively.Optical microscope,universal testing machine,scanning electron microscope and chemical workstation were used to analyze the effects of different welding speeds on the microstructure,mechanical properties and corrosion resistance of the samples.The results show that the welded joint consists of stir zone(SZ),thermo mechanical affected zone(TMAZ),heat affected zone(HAZ)and base metal zone(BM).Compared with the retreating side(RS),the boundary between TMAZ and SZ is more obvious on the advancing side(AS).When the welding speed is increased from 30 mm/min to 80 mm/min,the tensile strength and elongation of the joint first increase and then decrease.When the welding speed is 60 mm/min,the tensile strength reaches the maximum value of 190.3 MPa,which can reach 76%of the base metal(250.3 MPa).With the increase of welding speed,the corrosion resistance also shows a trend of first getting better and then decreasing.Under the conditions of rotating speed of 1200 r/min and welding speed of 60 mm/min,the corrosion resistance is the best.At this time,the maximum self-corrosion voltage is−1.44 V,and the minimum self-corrosion current density is 4.5×10^(−5)A/cm^(2).
作者
雷朱坦
耿家源
Lei Zhutan;Geng Jiayuan(Jingzhou University,Jingzhou 434000,Hubei,China)
出处
《焊接》
北大核心
2023年第1期50-54,共5页
Welding & Joining
基金
湖北省自然科学基金资助项目(2019CFC909)
湖北省教育厅科学技术研究计划指导性项目(B2021429)
荆州学院科学研究基金资助项目(2021KY05)。
关键词
搅拌摩擦焊
AZ31镁合金
显微组织
力学性能
腐蚀性能
friction stir welding
AZ31 magnesium alloy
microstructure
mechanical properties
corrosion resistance
